It is well known that opening cylinders for open-end spinning machines are equipped with a cylindrical ring serving as a needle support and having radial borings into which the needles are inserted, each of said needles consisting of a cylindrical needle shaft and a tapered needle point. In the context of needle rings of this kind, it is also well known to provide them with graduated borings for the needles, that is to say with borings which show in the outer ring surface a substantially bigger diameter than the needles, in order to avoid that the material to be manufactured adheres and that thereby the needle ring is provided with a felted coating covering the needle points.
This construction is quite expensive because of the fact that for each boring two cycles of operations are necessary. In addition, this construction has the disadvantage that the needles, the shaft length of which amounts only to approximately 2/3 of the depth of the borings, are merely held on this length so that they may get loose and, due to the great centrifugal forces, be thrown out.